Breast cysts are fluid-filled sacs inside the breast, which are usually benign (not cancer). You can have one or many breast cysts and they can happen in one or both breasts. They are often described as round or oval lumps with distinct edges. A breast cyst usually feels like a grape or a water-filled balloon, but sometimes a breast cyst can feel firm. Breast cysts usually do not require treatment unless a cyst is large, painful and/or uncomfortable. In that case, draining the fluid from a breast cyst, by a breast surgeon, can ease symptoms.

Breast cysts are common in women before menopause, between ages 35 and 50 years old but can be found in women of any age.

Breast cysts may be found in one or both breasts. Signs and symptoms of a breast cyst include:

  • A smooth, easily movable round or oval lump with distinct edges
  • Nipple discharge that may be clear, yellow, straw-colored or dark brown
  • Breast pain or tenderness in the area of the breast lump
  • Increase in breast lump size and breast tenderness prior to your period
  • Decrease in breast lump size and resolution of other symptoms after your period

Having breast cysts does NOT increase your risk of breast cancer. But having cysts may make it more difficult to find new breast lumps or other changes that might need evaluation by your doctor. Be familiar with how your breasts normally feel, so if you feel any new breast lumps that persist after a menstrual period, or if an existing breast lump grows or changes, see your healthcare provider.

Breast cysts may be defined by their size (microcysts, macrocysts) or by their complexity (simple cysts, complex cysts). If one of the above types of breast cysts is palpated and/or seen on routine breast imaging, no further workup is usually required. If the area is painful and/or uncomfortable, consultation with a breast surgeon for a cyst aspiration will be advised.